SPCCI Engine Control Combating High-Speed Noise
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Solution Overview
Problem
Compression-ignition engines experience excessive noise and vibration harshness (NVH) at high engine speeds due to loud combustion noise, which is not effectively addressed by existing technologies.
Innovation Solution
A control system that employs Spark Controlled Compression Ignition (SPCCI) combustion, combining spark ignition and self-ignition, where a spark plug ignites the mixture gas to initiate combustion through flame propagation, followed by self-ignition of unburned gas, with advanced fuel injection timing and swirl flow to reduce noise and improve fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If compression ignition combustion is used, then fuel efficiency is improved, but combustion noise and NVH increase
Solution Approach 1:
The patent combines spark ignition and compression ignition into a hybrid combustion mode. The spark plug initiates combustion in a controlled manner, while the compression ignition process is simultaneously utilized. This merging of two combustion mechanisms allows the engine to achieve the fuel efficiency benefits of compression ignition while suppressing the excessive combustion noise through the controlled spark ignition process.
2Power
If self-ignition timing is advanced, then power output is improved, but combustion noise increases
Solution Approach 1:
The control device monitors combustion characteristics and adjusts the spark ignition timing and fuel injection timing based on detected combustion state. This feedback control allows the system to optimize the balance between power output and combustion noise by dynamically adjusting ignition parameters according to actual combustion conditions, preventing excessive noise while maintaining power.
3Productivity
If engine speed is increased, then productivity is improved, but NVH exceeds allowable value
Solution Approach 1:
The patent implements dynamic adjustment of ignition timing and fuel injection timing based on engine operating conditions. The control device continuously adapts the spark ignition and compression ignition parameters according to engine speed, load, and temperature conditions. This dynamic control enables the engine to maintain low NVH across a wide operating range, including high-speed operation where productivity is enhanced.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The SPCCI combustion mode effectively reduces combustion noise and NVH while enhancing fuel efficiency by controlling the self-ignition timing and swirl flow, allowing for stable operation at high engine speeds.
Implementation Method 1
a spark plug ignites the mixture gas to initiate combustion through flame propagation
Implementation Method 2
combustion through flame propagation
Implementation Method 3
heat generated by this combustion raises the temperature inside the combustion chamber
Implementation Method 4
combustion of unburned mixture gas by self-ignition
Data Source
AI summary
A control system of a compression-ignition engine is provided, which includes an engine configured to cause combustion of a mixture gas inside the combustion chamber, an injector attached to the engine and configured to inject fuel into the combustion chamber, a spark plug disposed to be oriented into the combustion chamber and configured to ignite the mixture gas inside the combustion chamber, and a controller connected to the injector and the spark plug and configured to operate the engine by outputting a control signal to the injector and the spark plug, respectively. After the spark plug ignites the mixture gas to start combustion, unburned mixture gas combusts by self-ignition. The controller outputs the control signal to the injector so that a fuel injection timing is advanced when the engine operates at a high speed than at a low speed.